Cyclonic surface cleaning apparatus with a spaced apart impingement surface

ABSTRACT

A surface cleaning apparatus comprises a cyclone having a dirt outlet with an impingement surface positioned in a dirt collection chamber and spaced up to 50 mm, preferably from 8 to 30 mm, from the dirt outlet.

FIELD

This application relates to surface cleaning apparatus, such as vacuum cleaners.

BACKGROUND

The use of a cyclone, or multiple cyclones connected in parallel or series, is known to be advantageous in the separation of particulate matter from a fluid stream. Currently, many vacuum cleaners, which are sold for residential applications, utilize at least one cyclone as part of the air filtration mechanism.

A difficulty experienced with cyclonic separators is the re-entrainment of the separated particulate matter back into the outgoing fluid flow. Deposited particles exposed to a high-speed cyclonic flow have a tendency to be re-entrained.

Plates positioned in cyclone containers have been used to divide a cyclone container into an upper cyclone chamber, which is positioned above the plate, and a lower dirt collection chamber, which is positioned below the plate. See for example Conrad (U.S. Pat. No. 6,221,134).

It has been taught that the distance between a dirt outlet of a cyclone and a flat surface below the dirt outlet should be less than 8 mm or between 30 mm and 70 mm. See Dyson, U.S. Pat. No. 5,858,038 as well as U.S. Pat. No. 6,553,612 and U.S. Pat. No. 6,581,239. As stated in U.S. Pat. No. 5,858,038, it had previously been assumed that as large a distance as possible between a base surface and the cone opening of a cyclone is desirable. This allowed more volume in the collector for separated dirt and dust to accumulate before emptying was required and was also thought to reduce the likelihood of separated dirt and dust becoming re-entrained into the airflow. However, in U.S. Pat. No. 5,858,038 it was stated that maxima of separation efficiency for different sizes of cyclone and collector occur when the distance between the base surface and the cone opening lies in the range 30 mm to 70 mm and, in addition, a distance of less than 8 mm, particularly around 4 mm to 6 mm, is highly efficient.

SUMMARY

In accordance with this invention, a surface cleaning apparatus is provided which includes a cyclone having a dirt outlet and an impingement surface positioned distal to the dirt outlet. The impingement surface is may be positioned from 8 to 30 mm, preferably 12 to 25 mm from the dirt outlet. Preferably, the impingement surface is provided in a dirt collection chamber.

In a particularly preferred embodiment, the cyclone is inverted (i.e. the air inlet and the air outlet are provided in a lower portion of the cyclone) and the dirt outlet is provided in an upper portion of the cyclone. Accordingly, in such an embodiment, the impingement surface is positioned above the dirt outlet.

In accordance with such an embodiment, it is preferred that the dirt collection chamber surrounds at least a portion of, and preferably all of, the cyclone. The impingement surface may be a floor or lid of the dirt collection chamber or may be suspended therefrom.

In accordance with this aspect of the invention, there is provided a surface cleaning apparatus comprising:

(a) a dirty air inlet;

(b) a filtration apparatus comprising a cyclone downstream from the dirty air inlet, the cyclone having a dirt outlet;

(c) an impingement surface spaced up to 50 mm, preferably from 8 mm to 30 mm, from the dirt outlet;

(d) a dirt collection chamber in communication with the dirt outlet;

(e) a suction motor; and,

(f) a clean air outlet downstream from the suction motor.

In one embodiment, the cyclone has a longitudinal axis, an opening is provided between the impingement surface and the dirt outlet and separated material travels at an angle to the longitudinal axis as it travels from the cyclone outlet to the dirt collection chamber.

In any embodiment, separated material may travel generally transverse to the longitudinal axis as it travels between the cyclone outlet and impingement surface. Preferably, the space between the cyclone outlet and impingement surface extends all that way around the cyclone outlet (e.g., there may be an annular gap between the impingement surface and the dirt collection chamber sidewall)

In any embodiment, the cyclone may be frusto-conical.

In some embodiments, the cyclone is inverted such that the dirt outlet is an upper dirt outlet.

In any embodiment, the impingement surface may be positioned in the dirt collection chamber and may be other than a wall that defines the volume of the dirt collection chamber.

In some embodiments, the dirt collection chamber is positioned around at least a portion of the cyclone, the filtration apparatus comprises a lid positioned over the dirt collection chamber and the cyclone, and the impingement surface comprises a portion of the lid. Preferably, the impingement surface comprises a plate positioned above the upper dirt outlet and below the lid. More preferably, the plate is suspended from the lid.

In some embodiments, the dirt collection chamber has a floor and the impingement surface is spaced from the floor. Preferably, the dirt collection chamber is positioned below the dirt outlet. Alternately, or in addition, the dirt outlet is in a lower portion of the cyclone.

In some embodiments, the dirt collection chamber is positioned around at least a portion of the cyclone.

In some embodiments, the dirt collection chamber has an openable portion and the cyclone has an openable portion, whereby both the cyclone and the dirt collection chamber are openable such that the dirt collection chamber and the cyclone are emptyable.

In some embodiments, the dirt collection chamber has a lower moveable dirt collection chamber floor, the cyclone has a lower moveable cyclone floor connected to the lower moveable dirt collection chamber floor, whereby both the cyclone floor and the dirt collection chamber floor are moveable concurrently such that the dirt collection chamber and the cyclone are concurrently emptied.

In some embodiments, the dirt collection chamber floor and the cyclone floor comprise a pivoting bottom of the filtration apparatus.

In some embodiments, the dirt collection chamber is removable from the surface cleaning apparatus for emptying.

In any embodiment, the cyclone may have a longitudinal axis that extends generally horizontally (e.g., within 30, preferably within 15 and most preferably within 5 degrees of horizontal) when the surface cleaning apparatus is in use.

Surprisingly, despite the teaching of the prior art, it has been determined that the dirt separation efficiency of the cyclone is enhanced by positioning the impingement surface between 8 and 30 mm from the dirt outlet. Preferably, the impingement surface is positioned 12 to 25 mm from the dirt outlet.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages of the instant invention will be more fully and completely understood in conjunction with the following description of the preferred embodiments of the invention in which:

FIG. 1 is a side elevational view of a preferred embodiment of a vacuum cleaner in accordance with this design wherein the outer casing surrounding the cyclone and forming an outer wall of a dirt collection chamber is optionally transparent;

FIG. 2 is a perspective view from the front and the right side of the vacuum cleaner of FIG. 1;

FIG. 3 is a cross-section along the line 3-3 in FIG. 2;

FIG. 4 is a schematic drawing of the vacuum cleaner of FIG. 1 showing the airflow passage therethrough;

FIG. 5 is a perspective view from the bottom of the vacuum cleaner of FIG. 1 wherein the bottom of the first and second housings is open;

FIG. 6 is a perspective view of the bottom of the vacuum cleaner of FIG. 1 wherein the first and second housings are closed but an access door is open;

FIG. 7 is a side elevation view of an alternate embodiment of a vacuum cleaner wherein the dirt collection chamber is slidably mountable on the cyclone housing and separately removable from the vacuum cleaner;

FIG. 8 is a perspective view of FIG. 7;

FIG. 9 is a longitudinal section through the upper casing of the vacuum cleaner of FIG. 7;

FIG. 10 is a top plan view of the dirt chamber of FIG. 7 with the separation plate shown in the horizontal position; and,

FIG. 11 is a longitudinal section through an alternate embodiment of a vacuum cleaner in accordance with this invention.

DETAILED DESCRIPTION

As shown in FIGS. 1-6, a surface cleaning apparatus comprises a vacuum cleaner 10 having a filtration apparatus having at least one cyclone.

The filtration apparatus may be of any design or configuration. As exemplified, surface cleaning apparatus 10 has a first housing 12 and a second housing 14. First housing 12 comprises at least one cyclone 16 and a dirt collection chamber 18 and second housing 14 houses at least one and preferably a plurality of filters which, preferably, in order, comprise foam filter 20, felt filter 22 and HEPA filter 24 followed in the downstream direction by suction motor 26. It will be appreciated that only a single filter may be provided. Dirty air entrained in dirty air inlet 38 travels through the filtration apparatus, through suction motor 26 and exits the surface cleaning apparatus via clean air outlet 60. However, a side by side construction need not be used. For example, as shown in FIG. 7, a surface cleaning apparatus 10 has a first cyclonic cleaning stage comprising a single cyclone 150 having a dirt collection chamber 152 and a second cyclonic cleaning stage comprising a plurality of second stage cyclones 154 in parallel.

It will be appreciated that, surface cleaning apparatus may be a vacuum cleaner, a carpet extractor, a bare floor cleaner or the like. As exemplified, the surface cleaning apparatus is hand held. However the surface cleaning apparatus may be configured as an upright vacuum cleaner, a stick vacuum cleaner, a canister vacuum cleaner, a backpack or shoulder strap vacuum cleaner or other configuration known in the art. The surface cleaning apparatus may have a single cyclonic cleaning stage, which may be of any construction known in the art, or a plurality of cyclonic cleaning stages, which may be of any construction known in the art, e.g. they may comprise a single cyclone or a plurality of cyclones in parallel.

In accordance with this invention, cyclone 16, 150, 154 has a dirt outlet 28 and an impingement surface 30 spaced from dirt outlet 28 in dirt collection chamber 18. It will be appreciated that cyclone 16 may be of any construction (e.g., it may be cylindrical, frusto-conical or of other configuration). Cyclone 16 may be a cyclonic stage for a surface cleaning apparatus wherein the cyclonic stage consists of a single cyclone.

Alternately, a cyclonic stage may comprise a plurality of cyclones 16, 150, 154 in parallel, some or each of which has an impingement surface 30. Impingement surface 30 is spaced a distance D from outlet 28 wherein distance D is up to 50 mm, preferably 8-50 mm, more preferably 8 to 30 millimeters and, most preferably from 12 to 25 millimeters (see for example FIG. 3).

Preferably, as exemplified, impingement member 30 is spaced from a wall of dirt collection chamber. However, in alternate embodiments, impingement member may be a wall of dirt collection chamber provided the wall is spaced a distance D from dirt outlet 28. As exemplified, impingement member 30 is flat. It will be appreciated that, in alternate embodiments, it may be of varying shapes provided it is spaced a distance D from dirt outlet 28 and faces dirt outlet 28.

As exemplified in FIG. 3, cyclone 16 is inverted and dirt out 28 may be an upper dirt outlet positioned in dirt collection chamber 18 if air inlet 34 is positioned adjacent to the floor. In such an embodiment, impingement surface 30 may be a part of lid 32 of dirt collection chamber 18, e.g., mounted to or suspended by a post or the like from lid 32. Alternately, impingement surface may be mounted to a sidewall of dirt collection chamber 18 and/or cyclone 16. In further embodiments, a wall of dirt collection chamber 18 facing dirt outlet 28 may comprise the impingement surface 30. However, it is preferred that the impingement surface is other then a portion of a wall of dirt collection chamber 18 facing dirt outlet 28 and is preferably spaced therefrom as exemplified in FIG. 3. If lid 32 is removably mounted to cyclone 16, the impingement surface 30 is removable with lid 32.

If cyclone 16 is non-inverted, then dirt outlet 28 of cyclone 16 is in a lower portion of cyclone 16, as exemplified in FIGS. 7-10, and impingement surface may be positioned below dirt outlet 28. In either case, impingement surface 30 is spaced from dirt outlet 28 and the space between dirt outlet 28 and impingement surface 30 is a passage between cyclone 16 and dirt collection chamber 18. Cyclone 16 may have a longitudinal axis A as shown in FIG. 9. The separated material travels at an angle to the longitudinal axis as it travels from cyclone outlet 28 to dirt collection chamber 18, and preferably transverse thereto. Alternately, as shown in FIGS. 7-10, cyclone 16, 150, 154 may be non-inverted. Alternately, as shown in FIG. 11, cyclone 16, 150, 154 may be oriented such that longitudinal axis A extends horizontally when the surface cleaning apparatus is in use.

As exemplified in FIG. 3, cyclone 16 is an inverted cyclone. Accordingly, cyclone 16 has a lower air inlet 34 and a lower air outlet 36. Air inlet 34 is positioned downstream from dirty air inlet 38 of surface cleaning nozzle 40. Surface cleaning nozzle 40 may be any surface cleaning nozzle known in the art. Air inlet 34 of cyclone 16 may be in airflow communication with surface cleaning nozzle 40 in any manner known in the art. The exact structure of surface cleaning nozzle 40 and the communication passage between surface cleaning nozzle 40 and air inlet 34 will vary depending if the surface cleaning apparatus is an upright vacuum cleaner, canister vacuum cleaner or, as exemplified, a portable hand held vacuum cleaner. In operation, air will enter cyclone 16 through inlet 34 and travel upwardly, as exemplified in FIG. 4. The air will then travel downwardly to exit cyclone 16 via outlet 34. As shown in FIG. 4 by the hatched arrows, dirt will exit upwardly through outlet 28 and deposit on dirt collection chamber floor 42. In addition, some of the heavier particulate matter may not be entrained in the air stream and may be deposited on cyclone floor 44.

In an alternate embodiment, it will be appreciated that cyclone 16 need not be inverted but may be of any configuration or orientation provided that impingement surface 30 or surfaces 30 are positioned spaced from dirt outlet 28. The cyclone may accordingly be an upright cyclone or a cyclone having a single direction of travel of the air.

FIGS. 7-10 show an exemplary embodiment of vacuum cleaner 10 with an upright cyclone 16 wherein dirt outlet 28 is in a lower portion of cyclone 16 and the floor of dirt collection chamber 18 is below dirt outlet 28. In operation, a user may grasp handle 54 to maneuver surface cleaning nozzle 40 over a surface to be cleaned. The dirty air passes from inlet 38, through cleaning nozzle 40 to spine 130, which preferably comprises a hollow tube, and then passes into cyclone 16 via air inlet 34 before it spirals downwards towards impingement surface 30, travels upwards into vortex finder 36 and passes through optional filter 138, or filters as disclosed herein, to suction motor 26. The airflow exits as clean air through clean air outlet 60.

Material entrained in the dirty airflow separates as it travels at an angle to longitudinal axis A as it travels from cyclone outlet 28 to dirt collection chamber 18, and preferably transverse thereto.

As shown in FIGS. 7-9, collection chamber 18 may be removably mounted to facilitate emptying. To this end, dirt collection chamber 18 may comprise a flange 132 which may be slidably received by guide 134 for mounting dirt collection chamber 18 under cyclone 16. In operation, a user may grasp at handle 136 when removing and replacing collection chamber 18 under cyclone 16.

As exemplified in FIG. 10, impingement surface 30 may be mounted to the sidewall of dirt collection chamber 18, producing a substantially annular gap E between the outer wall of impingement surface 30 and the inner wall of dirt collection chamber 18 (see FIG. 9). In other embodiments, impingement surface 30 may be supported from below or any other position producing an annular gap or essentially an annular gap and, as exemplified, spaced above the floor of dirt collection chamber 18.

As exemplified in FIGS. 1-6, cyclone 16 is a frustoconical cyclone having cylindrical portion 46 and frustoconical portion 48. Alternately, or in addition to the orientation of cyclone 16, it will be appreciated that cyclone 16 may be cylindrical, entirely frustoconical or any other shape known in the art.

As exemplified in FIG. 3, cyclone outlet 36 of cyclone 16 comprises a vortex finder that extends inwardly into the cyclone chamber defined by cyclone 16. Outlet 36 preferably comprises a generally cylindrical passage, i.e. vortex finder, having an inlet 50 and an outlet 52. It will be appreciated that, in an alternate embodiment any outlet or vortex finder known in the art for cyclones may be utilized.

In some embodiments, inlet 50 may be covered by a screen, shroud or filter as is known in the art. However, it is preferred that vortex finder 36 is unobstructed, i.e., no screen, shroud or filter is provided on inlet 50. Accordingly, as exemplified in FIG. 3, vortex finder 36 is not surrounded by a screen, shroud or filter and no physical separation member is positioned in the cyclone chamber of cyclone 16. Accordingly, no filtration or screen member interior of cyclone 16 requires cleaning. Elongate material such as hair or fibre can become adhered to a shroud, requiring the shroud to be manually cleaned. If the shroud is inside the cyclone chamber, then the chamber may be openable sufficiently to permit a user to insert their hand to clean the shroud, or to remove the shroud for cleaning. Accordingly, it will be appreciated that bottom 44 need not be openable to permit a screen or a shroud or filter associated with inlet end 50 of outlet 36 to be cleaned. Preferably, a screen is positioned downstream from cyclone 16 and upstream from the pre-motor filters. For example, a screen 78 is preferably provided. The material that would otherwise clog a screen or shroud that surrounds inlet 50 may be retained by optional screen 78 which may be larger than a screen in a cyclone chamber.

As exemplified in FIGS. 1-6, vacuum cleaner 10 comprises a hand held vacuum cleaner. Accordingly, vacuum cleaner 10 may be provided with handle 54, which is affixed to lid 32 and lid 58 of second housing 14. Handle 54 may alternately be affixed to any other portion or portions of vacuum cleaner 10 as is known in the art. Optionally, as exemplified, on/off switch 56 may be provided on handle 54. On/off switch 56 may alternately be provided on any other portion of vacuum cleaner 10.

As exemplified in FIG. 3, suction motor 26 is positioned in second housing 14, preferably with a suction fan provided below the electric motor. Clean air outlet 60 is provided downstream from suction motor 26. An optional post-motor filter may be provided downstream from suction motor 26, such as in post-motor filter housing 62, which may be accessible via post motor filter housing door 64, which could be pivotably mounted to second housing 14.

While the use of the impingement surface is exemplified in a surface cleaning apparatus having side-by-side housings 12, 14, it will be appreciated that this design may be used in any vacuum cleaner configuration, such as an upright vacuum cleaner, which is exemplified in FIGS. 7-9.

Preferably, dirt collection chamber 18 surrounds at least a portion of and, as exemplified, preferably all of cyclone 16. Accordingly, cyclone 16 may be positioned in dirt collection chamber 18 and, preferably, generally centrally therein.

In accordance with this optional preferred embodiment, vacuum cleaner 10 may be configured such that the dirt collected on floor 44 of cyclone 16 is emptied at the same time as dirt collected on floor 42 of dirt collection chamber 18. The following description refers to the embodiment of FIGS. 1-6 wherein the openable end of the dirt collection camber is the dirt collection surface (floor 42). However, in an alternate embodiment, it will be appreciated that the openable portion need not be the dirt collection surface. For example, referring to FIG. 11, the openable portion may be the end of dirt collection chamber 152 to which impingement member 30 is attached. Accordingly, the reference to “upper” and “lower” and “floor” are for convenience in the following discussion and relate to a preferred embodiment.

As exemplified, floor 42 and floor 44 are both movable and connected to each other whereby both floors 42 and 44 are concurrently movable such that dirt collection chamber 18 and cyclone 16 are concurrently emptied. It will be appreciated that, in an alternate embodiment, floor 42 and 44 may be separately movable. Referring to FIG. 5, floors 42 and 44 may comprise a pivoting bottom of first housing 12 and, alternately, of the filtration apparatus (e.g. housings 12 and 14 of this embodiment). Accordingly, as seen in FIG. 5, when floors 42 and 44 are opened, both cyclone 16 and dirt collection chamber 18 may be emptied by holding vacuum cleaner 10 in the upright position (as shown in FIG. 1). Accordingly, the dirt will fall out of collection chamber 16 and cyclone 16 and will fall downwardly off of floors 42 and 44.

As shown in FIG. 5, housings 12 and 14 have a pivoting bottom 66, which is secured to each of housings 12 and 14 by a pivot 68. In the closed position exemplified in FIGS. 1 and 4, pivoting bottom 66 is secured in position by latch 70. Latch 70 may have a button 72 which, when pressed, causes arm 74 to move outwardly thereby disengaging a flange provided on the bottom end of arm 74 from flange 76 provided on pivoting bottom 66. A gasket or other sealing member may be provided at the interface of housings 12 and 14 and pivoting bottom 66 to provide an air tight or fluid tight seal. It will be appreciated that bottom 66 may be moveable in any other direction by any other means known in the art and may optionally be removable from housings 12, 14 for emptying. Further, bottom 66 may be moveably secured in position by any other means known in the art and need not be connected to surface cleaning apparatus 10 for relative motion thereto.

As exemplified in FIG. 5, outlet 36 is provided as part of floor 42, and is preferably integrally molded therewith. In an alternate embodiment, it will be appreciated that outlet 36 need not be removable from cyclone 16 with floor 42.

In an alternate embodiment, it will be appreciated that only floors 42 and 44 may be pivotally mounted to housing 12. In such an embodiment, foam filter 20 may remain sealed when cyclone 16 and dirt collection chamber 18 are emptied. In an alternate embodiment, a side-by-side of housings 12, 14 design as exemplified in FIG. 1 need not be utilized. In such a case, floor 42 and floor 44 may comprise the entire floor of the filtration assembly.

If bottom 66 opens both housings 12 and 14, then it will be appreciated that dirt positioned on the upstream surface of filter 20 may be emptied when bottom 66 is opened.

Optionally, in any embodiment, a filtration member is provided adjacent outlet 36 and, preferably, in sealing engagement with outlet 52. Referring to FIG. 3, filtration member 78 is positioned on rear surface 84 of floor 44 and overlies outlet 52. Accordingly, air that exits outlet 36 travels through filtration member 78. The air then travels through filtration chamber 80 and travels laterally to outlet 86, which is in air flow communication with headspace 88 below filter 20.

Preferably, filtration member 78 comprises a screen, such as an open mesh screen, e.g., a wire mesh screen or, alternately, a plastic mesh screen.

An access door 82 may be provided to permit access to filtration member 78 such that filtration member 78 may be cleaned. Access door may be any door that is movably mounted in overlying relationship to filtration chamber 80. As exemplified in FIG. 6, access door 82 comprises the lower half of filtration chamber 80 and is pivotally mounted by pivot 90 to pivoting bottom 66. Access door 82 may be opened by utilizing a latch 70, which engages flange 92 provided on the front end of access door 82. A sealing gasket or other sealing member known in the art may be utilized to provide an air tight or fluid tight seal for filtration chamber 80. Any other securing member known in the art may be used. Further door 82 may be removable and need not be connected to surface cleaning apparatus 10 for relative motion thereto.

Preferably, filtration member 78 is mounted and, more preferably, movably mounted and, most preferably, removably mounted to access door 82. As shown in FIG. 6, filtration member 78 is pivotably mounted to the inner surface of access door 82. Accordingly, when a user desires to clean filtration member 78, it may be pivoted in the direction shown by arrow A in FIG. 6 to an open or cleaning position. It will be noticed that access door 82 may be opened independently of pivoting bottom 66. In an alternate embodiment, it will be appreciated that a pivoting bottom 66 need not be provided.

Preferably, at least a portion of and, more preferably, all of access door 82, which as exemplified is the outer wall of filtration chamber 80, is transparent. Accordingly, a user may lift the vacuum cleaner, invert the vacuum cleaner or tilt the vacuum cleaner on its side to view filtration member 78 and determine whether filtration 78 requires cleaning or, alternately, replacement.

It will also be appreciated that any of the aforementioned embodiments may be used singly or in any particular combination or sub-combination of the remaining features listed above.

Although the invention has been described in conjunction with specific embodiments thereof, if is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. 

1. A surface cleaning apparatus comprising: (a) a dirty air inlet; (b) a filtration apparatus comprising a cyclone downstream from the dirty air inlet, the cyclone having a dirt outlet; (c) an impingement surface spaced up to 50 mm from the dirt outlet; (d) a dirt collection chamber in communication with the dirt outlet; (e) a suction motor; and, (f) a clean air outlet downstream from the suction motor.
 2. The surface cleaning apparatus of claim 1 wherein the impingement surface is spaced from 8 to 30 mm from the dirt outlet.
 3. The surface cleaning apparatus of claim 1 wherein the cyclone has a longitudinal axis, an opening is provided between the impingement surface and the dirt outlet and separated material travels at an angle to the longitudinal axis as it travels from the cyclone outlet to the dirt collection chamber.
 4. The surface cleaning apparatus of claim 3 wherein separated material travels generally transverse to the longitudinal axis as it travels between the cyclone outlet and impingement surface.
 5. The surface cleaning apparatus of claim 1 wherein the cyclone is frusto-conical.
 6. The surface cleaning apparatus of claim 1 wherein the cyclone is inverted such that the dirt outlet is an upper dirt outlet.
 7. The surface cleaning apparatus of claim 1 wherein the impingement surface is positioned in the dirt collection chamber and is other than a wall that defines the volume of the dirt collection chamber.
 8. The surface cleaning apparatus of claim 7 as it depends from claim 6 wherein the dirt collection chamber is positioned around at least a portion of the cyclone, the filtration apparatus comprises a lid positioned over the dirt collection chamber and the cyclone, and the impingement surface comprises a portion of the lid.
 9. The surface cleaning apparatus of claim 8 wherein the impingement surface comprises a plate positioned above the upper dirt outlet and below the lid.
 10. The surface cleaning apparatus of claim 9 wherein the plate is suspended from the lid.
 11. The surface cleaning apparatus of claim 7 wherein the dirt collection chamber has a floor and the impingement surface is spaced from the floor.
 12. The surface cleaning apparatus of claim 11 wherein the dirt collection chamber is positioned below the dirt outlet.
 13. The surface cleaning apparatus of claim 12 wherein the dirt outlet is in a lower portion of the cyclone.
 14. The surface cleaning apparatus of claim 1 and wherein the dirt collection chamber is positioned around at least a portion of the cyclone.
 15. The surface cleaning apparatus of claim 6 wherein the dirt collection chamber has an openable portion and the cyclone has an openable portion, whereby both the cyclone and the dirt collection chamber are openable such that the dirt collection chamber and the cyclone are emptyable.
 16. The surface cleaning apparatus of claim 15 wherein the dirt collection chamber has a lower moveable dirt collection chamber floor, the cyclone has a lower moveable cyclone floor connected to the lower moveable dirt collection chamber floor, whereby both the cyclone floor and the dirt collection chamber floor are moveable concurrently such that the dirt collection chamber and the cyclone are concurrently emptied.
 17. The surface cleaning apparatus of claim 16 wherein the dirt collection chamber floor and the cyclone floor comprise a pivoting bottom of the filtration apparatus.
 18. The surface cleaning apparatus of claim 11 wherein the dirt collection chamber is removable from the surface cleaning apparatus for emptying.
 19. The surface cleaning apparatus of any claim 1 wherein the cyclone has a longitudinal axis that extends generally horizontally when the surface cleaning apparatus is in use. 